Golang Error Handling Proficiency

Introduction

The panic lab is designed to test your ability to handle unexpected errors in Golang.

Panic

The lab requires you to use the panic function to fail fast on errors that shouldn't occur during normal operation or that you aren't prepared to handle gracefully.

• Basic knowledge of Golang programming language.
• Familiarity with error handling in Golang.
• Understanding of the panic function in Golang.

## Running this program will cause it to panic, print
## an error message and goroutine traces, and exit with
## a non-zero status.

## When first panic in `main` fires, the program exits
## without reaching the rest of the code. If you'd like
## to see the program try to create a temp file, comment
## the first panic out.
$ go run panic.go
panic: a problem

goroutine 1 [running]:
main.main() /.../panic.go:12 +0x47
...
exit status 2

## Note that unlike some languages which use exceptions
## for handling of many errors, in Go it is idiomatic
## to use error-indicating return values wherever possible.

There is the full code below:

// A `panic` typically means something went unexpectedly
// wrong. Mostly we use it to fail fast on errors that
// shouldn't occur during normal operation, or that we
// aren't prepared to handle gracefully.

package main

import "os"

func main() {

    // We'll use panic throughout this site to check for
    // unexpected errors. This is the only program on the
    // site designed to panic.
    panic("a problem")

    // A common use of panic is to abort if a function
    // returns an error value that we don't know how to
    // (or want to) handle. Here's an example of
    // `panic`king if we get an unexpected error when creating a new file.
    _, err := os.Create("/tmp/file")
    if err != nil {
        panic(err)
    }
}

Summary

In this lab, you learned how to use the panic function to handle unexpected errors in Golang. Remember to use panic only when necessary and to handle errors gracefully whenever possible.